Efficacy of oral sildenafil in patients with erectile dysfunction after radiotherapy for carcinoma of the prostate

Objectives. To determine the efficacy of sildenafil for patients with erectile dysfunction after radiotherapy for localized prostate cancer. Methods. Fifty patients with erectile dysfunction after radiotherapy were treated with sildenafil. Their median age was 68 years (range 54 to 78). All were treated with a three-dimensional conformal external beam radiotherapy approach, and the median dose prescribed to the planning target volume was 75.6 Gy. Patients were initially given 50 mg of sildenafil and instructed to use the medication on at least three occasions. They were then contacted to ascertain the efficacy of and tolerance to the medication. Results. Significant improvement in the firmness of the erection after sildenafil was reported in 37 patients (74%), 2 (4%) had partial improvement, and 11 (22%) had no response. Significant improvement in the durability of the erection was reported in 33 patients (66%), 3 (6%) had partial improvement, and 14 (28%) reported no improvement. Patients with partial or moderate erectile function before using sildenafil were more likely to benefit from the medication compared with those with absent function. Among 29 patients with erections classified as partial after radiotherapy, 26 (90%) had a significant response to the medication. In contrast, only 11 (52%) of 21 with erections classified as flaccid after radiotherapy had a significant response to the medication (P = 0.007). Conclusions. Sildenafil improved erectile function in greater than two thirds of patients with postradiotherapy impotence. Patients with less severe dysfunction are most likely to benefit from this intervention. (C) 1999, Elsevier Science Inc. All rights reserved.